Lock



E. N. JACOB] Aug. 9, 1938.

LOCK

Filed May 10, 1957 2 Sheets-sheaf: 1

Edward N. Jami Aug. 9, 1938. E, JACQBI 2,126,391

LOCK

Filed May 10, 1937 2 Sheets-Sheet 2 Edward N m Patented Aug. 9, 1938 PATENT OFFICE LOCK Edward N. Jacobi, Milwaukee, Wis., assignor to Briggs & Stratton Corporation, Milwaukee, Wis., a corporation of Delaware Application May 10, 1937, Serial No. 141,713

4 Claims.

This invention relates to improvements in locks and refers particularly to pin tumbler locks.

In certain types of pin tumbler locks, it is customary to assemble the cylinder with the casing from the rear. As a result, the joint between the cylinder and its casing is exposed at the front end of the look so that it is possible to insert a thin feeler between the cylinder and the wall of the bore to hold a sufiicient number of tumblers in their inoperative positions (to which they have been actuated by a picking tool) to permit the lock to be forced.

It is therefore an object of this invention to provide means for guarding the joint between the cylinder and the casing bore at its front end to preclude the insertion of a feeler.

It is also customaryin locks of this type to provide the desired finish for the front end of the look by directly plating the die-cast cylinder and easing. Plating the lock parts in this manner does not permit the best treatment of the die castings for corrosive resistance.

t is therefore a further object of this invention to provide the desired bright finish for the front end of the look by means of separate caps covering both the front of the cylinder and the front of the casing so as to permit treating the zinc alloy die castings by the best process for corrosive resistance.

Another object of this invention is to so design these caps which provide the desired bright finish for the front end of the look as to also protect the joint between the cylinder and the casing bore against the insertion of a thin feeler.

A further object of this invention is to provide simple and eflicient means for retaining the caps in position, which is so constructed that the caps may be readily applied after the cylinder and easing are assembled.

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawings illustrate several complete examples of the physical embodiment of the invention constructed in accordance with the best modes so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a side view of the front end portion of a lock embodying one form of this invention,

parts thereof being broken away and in section; Figure 2 is a front end view of this look with a portion thereof broken away;

Figure 3 is a perspective view showing the inner face of the cylinder cap and the outer end of the cylinder;

Figure 4 is a view similar to Figure 1, illustrating a slightly modified embodiment of the invention;

Figure 5 is a perspective view of the cylinder cap and the front end of the cylinder of the lock shown in Figure 4;

Figure 6 is a View similar to Figure 1, illustrating another modified embodiment of the invention;

Figure 7 is a front View of the lock shown in Figure 6; and

Figure 8 is a perspective View of the cylinder cap and the front end of the cylinder of the lock shown in Figure 6.

Referring now particularly to the accompanying drawings in which like numerals indicate like parts throughout the several views, the numeral 5 designates the casing of a pin tumbler lock which is bored as at 6 to receive a lock cylinder l. The lock is of the type wherein the cylinder is inserted into the bore 6 from its rear end and means (not shown) are provided for securing thecylinder in the casing.

The cylinder is provided with the customary .1

pin tumblers 8 (only one being shown) yieldingly urged into the cylinder by spring pressed drivers 9 mounted in the casing. The inner ends of the tumblers 8 extend into a keyway I!) to be accessible to a key insertable into the keyway by which the tumblers are lifted to bring the junction of their outer ends and the drivers 9 in line with the joint between the cylinder and the casing bore.

To protect the front end of the joint between As best shown in Figure 3, the mouth of the keyway it extends substantially entirely across the diameter of the cylinder and is of a size to receive an inward protrusion 14 formed on the cap 1 l. Theiprotrusion I4 is struck from the cap, as shown, and fits snugly within the mouth of the keyway so as to secure the cap against relative rotation with respect to the cylinder and at all times maintain its key opening IS in proper alignment with the mouth of the keyway.

Assembly of the cap H and the cylinder is effected by merely slipping the cap onto the front end of the cylinder. It is held in position against detachment by a ring-like cap l6 secured over the front end of the casing 5. The cap I6 has a hole I! approximately the diameter of the bore 6 so that the flange l2 of the cylinder cap is con fined beneath the inner peripheral edge portion of the cap IS.

The cap [6 is shaped to conform to the configuration of the front end of the casing and is secured in place by having its outer peripheral portion l8 fitted tightly about a rim I9 formed at the front end of the casing. The cap I6 is thus securely fastened to the casing and by extending over the flange [2 of the cylinder cap serves to hold the same in position.

Inasmuch as it is desirable to have a bright polished finish for the front end of the cylinder, the caps H and 16 are suitably plated and polished prior to their application to the cylinder and casing. In this manner, the desired finish is obtained for the front end of the look without necessitating plating the die-cast parts, thus allowing the most approved process to be employed for protecting the die castings against corrosion.

In the embodiment of the invention illustrated in Figures 4 and 5, the cylinder cap 20 consists of a dished plate to be fitted over the front end of the cylinder and having a rectangular opening 2| for alignment with the mouth of the keyway 22. The cap is held against rotation on the cylinder by two rearwardly directed tangs 23 which engage in notches or recesses 24 in opposite sides of the cylinder.

As in the embodiment previously described, the front end of the casing bore is counterbored as at 25 to receive the outer edge portion of the cap 20 which is of larger diameter than the cylinder so as to cover the joint between the cylinder and the casing bore. The cylinder cap is retained in position by a cap 26 which covers the front end of the cylinder to which it is securely fastened by having its peripheral portion 21 formed about an annular flange 28.

At its center, the cap 26 has ahole provided with an inwardly directed flange 29 to engage the face of the cap 20 and hold the same in place.

In the embodiment of the invention illustrated in Figures 6, '7 and 8, the lock casing 30 is noncircular in cross section, but in other respects is like that shown in Figure 1 and is bored to receive a cylinder 3|, the front end of the bore being counterbored as at 32. In this instance, the cylinder cap 33 is substantially a shallow cup with a peripheral flange 34 extending rearwardly therefrom to engage over the front end portion of the cylinder. A transverse substantially rectangular opening 35 in the face of the cap 33 provides a passage for the key in alignment with the mouth of the keyway 36, and rearwardly extending lugs or ears 3'! on the margins of the opening 35 engage in recessed portions 38 at the mouth of the keyway to secure the cap against rotation with respect to the cylinder.

As best shown in Figure 6, the outer surface of the annular flange 34 is stepped to provide a ledge 39 which engages in back of the edge of a hole 40 in the casing cap 4|. In this manner, the cylinder cap is retained in place upon securement of the cap 4|. The casing cap 4| conforms to the non-circular cross sectional shape of the casing and is fitted snugly thereover and secured in position by having a portion of its rear edge engage down into a recess 42 in the casing, as shown in Figure 6.

From the foregoing description taken in connection with the accompanying drawings, it will be readily apparent to those skilled in the art, that this invention provides. simple means for protecting pin tumbler locks of the character described against picking by the insertion of a thin feeler between the cylinder and. casing bore, and that the same means which is used to provide this protection also serves as a finish for the front end of the lock leaving the die-cast parts thereof free to be treated in the most desirable and approved manner for corrosion resistance.

What I claim as my invention is:

1. In a lock: a bored casing having a counterbore; a cylinder mounted in the bore with one end projecting into the counterbore; a cap overlying said end of the cylinder with its peripheral portion extending therebeyond, said end of the cylinder being spaced from the bottom of the counterbore so that the peripheral portion of the cap is held from contact with the casing; cooperating means on the cylinder and the cap to secure against relative rotation therebetween; and a ring-like cap secured over the adjacent end. of the casing with its inner peripheral portion pressing against the front of the cylinder cap to hold the same in firm engagement therewith and secure the cylinder against outward endwise movement.

2. In a lock: a bored casing having a counterbore; a cylinder mounted in the bore with one end projecting into the counterbore; a cap overlying said end of the cylinder with its peripheral portion extending therebeyond, said end of the cylinder being spaced from the bottom of the counterbore so that the peripheral portion of the cap is held from contact with the casing; coopcrating means on the cylinder and the cap to secure against relative rotation therebetween; and a ring-like cap of thin spring-like stock secured over the adjacent end of the casing with its inner peripheral portion pressing against the front of the cylinder cap to yieldingly hold the cylinder cap against the cylinder and urge the cylinder in one endwise direction.

3. In a look: a casing having a bore; a cylinder mounted therein and having diametrically opposite longitudinally extending grooves in its outer surface; a cap covering the front end of the cylinder with its peripheral portion extending out over the joint between the cylinder and the casing bore to prevent the insertion of a tool therebetween; cooperating means on the cylinder and cap for securing said cap against relative rotation including rearwardly directed diametrically opposite tangs formed on the peripheral portion of the cylinder cap and closely fitted into said diametrically opposite grooves in the outer surface of the cylinder; and a ring-like cap secured over the front end of the casing with its inner peripheral portion overlapping the cylinder cap to hold the same in place.

4. In a lock: a casing having a bore; a cylinder mounted therein and having diametrically opposite longitudinally extending grooves of different size in its outer cylindrical surface; a cap covering the front end of the cylinder with its peripheral portion extending out over the joint between the cylinder and the casing bore to prevent the insertion of a tool therebetween; a nonrotatable connection between said cap and the cylinder comprising, a tang projecting rearwardly from the peripheral portion of said cap and of a size to be closely fitted into the larger of said cylinder grooves, and another tang smaller than said first named tang projecting rearwardly from the peripheral portion of said cap at a point diametrically opposite said first named tang and adapted to be closely fitted into the smaller of said cylinder grooves; and a ring-like cap secured over the front end of the casing with its inner peripheral portion overlapping the cylinder cap to hold the same in place.

EDWARD N. JACOBI. 

